Display apparatus

ABSTRACT

A display apparatus having a keyboard for encoding elements for the display of various characters, symbols or graphs by the combination of dots on a cathode ray tube operated in accordance with the standard television system, and MOS (Metal Oxide Semiconductor) dynamic shift registers for storing the codes representing the characters, symbols on graphs to be displayed. A video signal according to the codes applies intensity modulation to the scanning lines or rasters thereby to effect the desired display on the cathode ray tube. Renewal of displayed character can be effected by displaying a cursor at a renewed position on the cathode ray tube and manipulating the keyboard.

United States Patent Primary Examiner-John W. Caldwell AssistantExaminer David L. Trafton Attorney-Craig, Antonelli & Hill ABSTRACT: Adisplay apparatus having a keyboard for encoding elements for thedisplay of various characters, symbols or graphs by the combination ofdots on a cathode ray tube operated in accordance with the standardtelevision system, and MOS (Metal Oxide Semiconductor) dynamic shiftregisters for storing the codes representing the characters, symbols ongraphs to be displayed. A video signal according to the codes appliesintensity modulation to the scanning lines or tasters thereby to effectthe desired display on the cathode ray tube. Renewal of displayedcharacter can be effected by displaying a cursor at a renewed positionon the cathode ray tube and manipulating the keyboard.

lnventors Nagaharu Hamada Hitachi-chi; Mot/oat Mlyanaltn, Kumagegun,Ynmaguehl-ken; YIIIIO Suzuki; hao Yasuda; Yukltaka Bayaahl, all ofHitachi shl, all of Japan Appl. No. 855,804 Filed Sept. 8, 1969 PatentedDec. 28, 1971 Assignee Hltaehl, Ltd.

Tokyo, Japan Priorities Sept. 9, 1968 Japan 43/6426 1; Jan. 30, 1969,Japan, No. 44/7110; Jan. 30, 1969, Japan, No. 44/8499 DISPLAY APPARATUS5 Claims, 21 Drawing Figs.

15. Cl. 340/324 A, 340/ 1 72.5 Int. Cl G06! 3/14 Field of Search 340/324A, 220

3 4 J 1 04 7A H'i'OCESSM/G my IG'YBOGRD mm AND HUM/7Z7? GOVT/POL W727?GEM/M701? DISPLAY BASIC CONTROL Patented Dec. 28, 1971 CHARACTFRSH ICE(Pf/7 )C/MMCTEP 18 Sheets-Sheet 1 CHARAcER SPACE r [-m L/NE 7 *L/NESPACELWESPACE' INVENTORS BY 11?,W Jilwadvmu ATTORNEYS Patented Dec. 28, 19713,631 ,457

18 Sheets-Sheet 8 3 4 6 7 J J S 2 DATA PROCESS/N6 CHARACTER MEMORYa-RAr0R DIS/OLA Y 5 r J 2 S KEYBOARD MEMORY BASIC AND HP/NTER CUNTROLCONTROL ONE ICl-MRACIFR CURSOR A r SHIFT PULSE I l SH/Fr PLL$I INVENTORSnmblhnm dl'ldacb moTaS mama usu sucuKi sap Y udul BY fiuKcRKa. Hu

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18 Sheets-Sheet 6 FIG. 60

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18 Sheets-Sheet 1 l 40 cmmcrzns 5 CHARACTERS 5 CHARACTERS lHl llllllllllllllllilllIIIIIIIHIIHI llIlHl DISPLAY WR/I'E m/ MEMORY46 IN VENTORSBY YUKfr-sk' 1311 Mu M Q ATTORNEYS Patented Dec. 28, 1971 3,631,457

18 Sheets-Sheet 15 INVENTOI6 Patented Dec. 28, 1971 3,631,457

18 Sheets-Sheet 14.

HOP/ZONTAL COUNTER COUNTER HOQ/ZONZ IL l4 POS/T/O/V HORIZONTAL DOTADDRESS 056005? n ml N V E N TO RS 3%) fr; :I K i 3500 Su 33s vi il BY6% H1 mum ATTOR NI'LYS Patented Dec. 28, 1971 18 Sheets-Sheet 1 BNQQQQMQ WMMQQQ? Patented Dec. 28, 1971 18 Sheets-Sheet 16 VERT/CALSYNCS/GML FIG I20 COUNTER VERTICAL ROS/T/ON COUNTER VERT/CAL OUT yi soo5mm? mg dd, YUKI INVENTOI6 *Nda.

si "M tsu ATTORNEYS Patented Dec. 28, 1971 18 Sheets-Sheet 17 S L l 2mumm w w mwwmaw hmm 0 olsPLAv APPARATUS BACKGROUND OF THE INVENTION 1.Field of the Invention This invention relates to a display apparatus.

2. Description of the Prior Art A remarkable increase in the amount ofinformation handled by electronic computers is seen as the size ofelectronic computers becomes larger, and therefore it is desired tosimplify the means available for man-machine communication.

Various types of character display apparatus, pattern display apparatusand the like have been developed and some of them have been disclosed,for example, in the Japanese in ine "Fuji" Vol. 12, No. 4 and theJapanese magazine OI-1M Feb. I968.

However, the known apparatus of this kind are relatively costly andinvolve economical problems. Thus, it is the present practice that theapparatus of this kind is not so popularly used as to match the increasein the amount of information in spite of the emphasis placed on thenecessity for such apparatus. These problems mainly arise from the factthat the apparatus employ a special cathode-ray tube in the displaysection which includes a complex control circuit. Therefore, theappearance of an economical display apparatus employing a cathode-raytube commonly used in commercial television sets and an inexpensivecontrol circuit are strongly required.

SUMMARY OF THE INVENTION The present invention proposes a displayapparatus in which intensity modulation is applied to scanning lines ofa cathoderay tube with suitable timing so as to display a character,symbol or pattern by an assembly of bright spots or dots, that is, by asuitable combination of horizontal and vertical dots. According to thepresent invention, the display section may merely consist of atelevision receiver of the standard television system, and circulatingmemories, such as delay line memories or dynamic shift registers, areemployed in the control circuit to obtain an inexpensive displayapparatus.

It is a primary object of the present invention to provide aninexpensive and highly reliable display apparatus.

Another object of the present invention is to provide a displayapparatus which can display patterns including a graph in spite of avery small memory capacity.

Other objects, features and advantages of the present invention will beapparent from the following detailed description taken in conjunctionwifli the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a diagram illustrating thebasic principle of the present invention.

FIG. 2 is a block diagram showing the basic structure of the presentinvention.

FIG. 3 is a block diagram for the explanation of a basic control circuitand a character-generating circuit in an embodiment of the presentinvention.

FIGS. 4 and 5 show a time chart for the explanation operation of thecircuits shown in FIG. 3.

FIG. 6a is a block diagram showing the structure of a memory 4 in theembodiment of the present invention.

FIG. 6b is a circuit diagram of one of the blocks shown in FIG. 60.

FIGS. 7a and 7b are block diagrams respectively showing the structure ofa memory control circuit and a cursor control circuit in the embodimentof the present invention.

FIGS. 80 and 8!: show a time chart for the explanation of the operationof the memory control and cursor control.

, FIG. 9 is a block diagram showing the structure of a circuit forwriting data from a keyboard in the memory in the embodiment of thepresent invention.

FIG. [0 shows a time chart for the explanation of operation of thecircuit shown in FIG. 9.

FIG. 11 is a diagram illustrating how a pattern and a character aresimultaneously displayed by the present invention.

FIGS. 12a through 12d illustrate a circuit diagram of another embodimentof the present invention for effecting a display as shown in FIG. 11.

FIG. 13 is a view showing the relation between FIGS. 12a, 12b, 12c andIZd.

FIG. 14 is a block diagram showing a practical example comprising acombination of a display apparatus and a television receiver.

FIG. I5 shows a time chart for the explanation of write-in operationwith a high-speed shift register.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will bedescribed with regard to an example in which a television receiver ofthe standard television system (horizontal synchronizing frequency of15.75 kHz. and vertical synchronizing frequency of 60 Hz. com monly usedin Japan and the United States is utilized in the display section of thedisplay apparatus according to the present invention.

FIG. 1 is a diagram illustrating the basic principle of the presentinvention. FIG. Ia shows diagrammatically a part of the display on thescreen of a cathode-ray tube. In FIG. la, y,, y,,-,ay y,, y,,-representthe scanning lines running across the face of a cathode-ray tube in thehorizontal direction (Ilyback lines are not shown herein), while 1,, x rx x,, represent the timing for applying intensity modulation to thescanning lines. It will be seen from FIG. Ia that, in accordance withthe present invention, intensity modulation is applied to the rasterswith suitable timing so as to display a character, symbol or pattern byan assembly of bright spots or dots. Thus, special deflection circuitsare not required for the display and a television receiver of thestandard television system can be utilized. In accordance with thepresent invention, the video signal corresponding to the respectiveraster may be controlled in a manner as seen in FIG. lb so that they candisplay a specific character or symbol. In the case of FIG. I, I4rasters are allotted to one line of a character or symbol to bedisplayed, with 7 rasters being used for display and the remainingrasters are used to provide a space between lines, while in thehorizontal direction, eight dots are allotted, with five dots used fordisplay and the remaining dots used to provide a space betweencharacters or symbols. According to this example, therefore, any desiredcharacter or symbol can be displayed by the combination of 35 dotsconsisting of five horizontal dots and seven vertical dots.

Referring to FIG. 2 which is a block diagram showing the basic structureof the present invention, the display apparatus comprises a keyboard andprinter unit I, a memory control circuit 2, a data processing unit 3such as a computer or data logger, a memory 4, a basic control circuit5, a charactergenerating circuit 6 and a display unit 7. The keyboardand printer unit I writes in desired characters or symbols and printsdisplayed characters or symbols for preservation. The memory controlcircuit 2 controls the acceptance and delivery of data between thekeyboard and printer unit I, the computer 3 and the memory 4 and readoutof data from the memory 4 for delivery to the character-generatingcircuit 6 for the sake of display. The memory 4 stores the code of thecharacters to be displayed on the screen and effects readout andwrite-in of data under the control of the memory control circuit 2. Thebasic control circuit 5 produces the horizontal and verticalsynchronizing signals to be applied to the display unit 7, and at thesame time, applies signals designating the position of the characters,space between characters and space between lines to thecharacter-generating circuit 6 and memory control circuit 2. Thecharacter-generating circuit 6 generates a video signal according to thetiming designated by the basic control circuit 5 on the basis of thecode supplied from the memory 4 and delivers the video signal to thedisplay unit 7. The display unit 7 displays a character or symbol on theface of a cathode ray tube when it receives the video signal describedabove and the synchronizing signals supplied from the basic controlcircuit 5. A display apparatus having a plurality of input units

1. A display apparatus comprising means for supplyinginformation-representing characters to be displayed, memory means forstoring said information to be displayed, memory control means forcontrolling the storage and rewrite of the information in said memorymeans, character-generating means for generating signals representingchAracters corresponding to the contents of said memory means,cathode-ray tube display means for displaying a character depending onthe output from said charactergenerating means, said display means beingprovided with a deflection system and a deflection control systemcorresponding to that of the standard commercial television receiver,and a basic control circuit having an oscillator generating a specificfrequency for applying control signals to said memory control means andcharacter-generating means with a predetermined timing, said memorymeans comprising a number of component memory means equal to the numberof bits forming characters to be displayed, said components memory meansbeing connected in parallel and each component memory means comprisingfirst and second circulating memories connected in cascade, said firstcirculating memory containing information for one horizontal sweep in aline of the display, said second circulating memory containinginformation for the remaining lines of the display, the output of saidfirst circulating memory being connected to said character-generatingmeans in control thereof, said memory control means including means forseparately controlling said first and second circulating memories.
 2. Adisplay apparatus as claimed in claim 1, in which said secondcirculating memory is divided into a plurality of blocks which arecontrolled by separate pulse trains.
 3. A display apparatus as claimedin claim 1, in which there is provided at least one pattern-generatingcircuit for generating preselected pattern elements and means forswitching connections between said character generating circuit and saidpattern generating circuit.
 4. A display apparatus as claimed in claim1, in which there are provided further memory means for preselectedpattern elements, which are interconnected with the remaining means inthe apparatus so as to allow a parallel operation with thefirst-mentioned memory means for the information of characters.
 5. Adisplay apparatus as claimed in claim 1, further including means forcontrolling and detecting the position of a cursor which means includesmeans for producing an output at a time earlier by predetermined bittime than the time when the cursor actually appears, and meansresponsive to said output for writing an external signal into saidmemory means at the address corresponding to the position of saidcursor.